find a string in none-English book

[saro1992]

English only contains 26 Character ,but some languages may contains more characters.in librera ,i cant search a single Chinese character use find function.i was told "need a longer string".

[jrpear]

Just to clarify this issue:

Often when reading a document in a language such as Chinese with thousands of characters, one wants to search for a single character, which may only appear once or twice in a hundred page document.

I want to do this in a Japanese etymological dictionary I'm using.

Right now this search impossible because trying to search the document for a single character gives an error:

Need a longer search string

I think the easiest solution to this is to just remove the search string length check. Most other PDF readers allow you to search for a single character (Okular, pdf.js, Xodo PDF Reader).